Vectors and matrices of intervals can be created by passing numerical matrices, char vectors or cell arrays to the <code>infsup</code> constructor. With cell arrays it is also possible to mix several types of boundaries.

octave:18> M = infsup (magic (3))

M = 3×3 interval matrix

[8] [1] [6]

[3] [5] [7]

[4] [9] [2]

octave:19> infsup (magic (3), magic (3) + 1)

ans = 3×3 interval matrix

[8, 9] [1, 2] [6, 7]

[3, 4] [5, 6] [7, 8]

[4, 5] [9, 10] [2, 3]

octave:20> infsup (["0.1"; "0.2"; "0.3"; "0.4"; "0.5"])

ans ⊂ 5×1 interval vector

[.09999999999999999, .10000000000000001]

[.19999999999999998, .20000000000000002]

[.29999999999999998, .30000000000000005]

[.39999999999999996, .40000000000000003]

[.5]

octave:21> infsup ({1, eps; "4/7", "pi"}, {2, 1; "e", "0xff"})

ans ⊂ 2×2 interval matrix

[1, 2] [2.220446049250313e-16, 1]

[.5714285714285713, 2.7182818284590456] [3.1415926535897931, 255]

When matrices are resized using subscripted assignment, any implicit new matrix elements will carry an empty interval.